ABSTRACT
Objective To describe the high-resolution CT(HRCT)findings of arc-welders with early pneumoconiosis and to evaluate manifestation in different course of disease.Methods Seventy-six arc-welders with a one to thirty-eight(mean,14)years history of exposure underwent CT and HRCT scanning.The extent of abnormalities were detected.The relations of age and year history of exposure were analysed in different groups.Results Thirty-eight welders(38/76,50%)showed positive characteristic findings with conventional CT.Predominant thin-section CT findings were poorly-defined centrilobular micronodules(18/76,23.7%),branching linear structure(20/76,26.3%).The mean age in group of branching linear structure[(39±9)years old]was elder than of poorly-defined centrilobular micronodules[(34±7)years old].There was no statistical difference between the two groups(t=-1.648,P＞0.05).The mean length of service at exposure in group of branching linear structure[(15±8)years]was longer than of poorlydefined centrilobular micronodules[(10±5)years].And the significant differences were showed between the two groups in the year history of exposure(t=-2.108,P＜0.05).Conclusions Poorly defined centrilobular micronodules and branching linear structures were the thin-section CT findings most frequently seen in patients with arc-welders'pneumoconiosis and the former may be one early stage characteristic finding of arc-welders'pneumoconiosis.HRCT is useful in achieving more accurate categorization of the parenchymal changes in arc-welders'pneumoconiosis.
ABSTRACT
Objective To improve the diagnostic value of MRI on orbital diseases,especially on benign and malignant tumors,through analyzing the characteristics of orbital diseases with dynamic contrast-enhanced MRI.Methods Forty-one patients with solitary orbital masses, including 31 benign tumors and 10 malignant tumors,underwent MR examinations. All the cases were verified by pathology.1.5 T MR system and head coil were employed.Conventional scan was performed with axial,sagittal,and coronal T_1WI,as well as axial T_2WI and the slice thickness of 4 mm.After the injection of contrast agents,dynamic contrast-enhanced MRI was immediately performed so as to observe dynamic changes of lesions.Enhancement rates(E%) was calculated and time-intensity curve was portraited according to the signal intensity of conventional scan and dynamic-contrast enhanced scan.SPASS Ver10.0 was used to do the statistical analysis,while cartographies were completed with Powerpoint.Results(1)Comparision between benign and malignant tumors in average enhanced rates of the 1~(st) minute: it was higher than 60% in malignant tumors,while lower than 60% in benign ones(P